Lab/Field Assignment GEL 103

1. LAB/FIELD
ASSIGNMENT
JAYCE GONZALES
GEL 103

2. INTRO
 My lab/field assignment was done in Eagle Rock, Los Angeles, California where I live. All my samples were
either near my house or the nearby park. Examples of life I found were some birds and trees which include the
palm tree, pine tree, and even a peacock. The rocks that I found were most likely decorative boulders as well as
some rocks I found along a trail in the park. I could not find any examples of Steno’s Laws and Principles as
well as unconformities which I will explain later on.
 All photos of life and rocks were taken by me.

3. GEOLOGICAL HISTORY OF THE LOS ANGELES BASIN
 The history of Eagle Rock’s geological formation ties in with the formation of the Los Angeles Basin.
 The geologic center for the Los Angeles Basin starts where the Los Angeles and Rio Hondo Rivers merge in the City of South Gate. Los Angeles
Basin was submerged underwater around 15 million years ago.
 “As surrounding mountain ranges (including the San Gabriel and Santa Monica ranges) shifted in a clockwise spiral, the underlying crust
stretched and cracked and released molten rock from below. The crust thinned and ‘collapsed,’ forming an immense geologic ‘bowl.’ Sand, silt and
clay from the sea and ancient rivers poured into the bowl. Microorganisms also poured into this hole, piling high in huge layers. These layers would
eventually become the oilfields of Los Angeles” (The Los Angeles Basin - A Huge Bowl of Sand, n.d.).
 The crust stopped stretching and the bowl began to shrink around 5 million years ago. “The hole filled in and seismic activity started pushing the
contents upward. Sediment also continued to flow from the mountains onto this growing mound.” (The Los Angeles Basin - A Huge Bowl of Sand,
n.d.).
 The sediment eventually started to rise above sea level and piled up to what is now known as the Los Angeles Basin.

4. LIFE

5. PEACOCK
 Peacock is a general term for the bird, but peafowl is technically the
correct terminology since it refers to both males and females.
 (Peacock=male, peahen=female)
 Some known types of peafowl are the Indian peafowl and the Green
peafowl.
 From genetic data, it is suggested that Indian and Green peafowl
diverged about 3 million years ago (Naish, 2013).
 “Fossil peafowl are known from the Miocene and Pliocene of Europe; they
were also present in Europe in the Early Pleistocene” (Naish, 2013).
Peahen outside my house

6. PEACOCK CONT.
 Modern peafowls are not native to the United States, they originate from India and Southeast Asia
 Peafowls were imported from India to Southern California by rich civilians around the 1880’s to show off their
status (Horspool, 2021).
 Today, peafowls can be found among many Southern California cities including Arcadia, Monrovia, Pasadena,
Altadena, and South Pasadena.

7. PALM TREE/CALIFORNIA PALM
 “The Arecaceae, the palm family, is a family of flowering plants belonging
to the monocot order Arecales” (Palm - New World Encyclopedia, n.d.).
 Palms appear in the fossil record around 80 million years ago during the
Late Cretaceous period.
 "Fossil records suggest that date palms were widespread throughout the
Mediterranean as far back as the Eocene epoch, which began about 56 million
years ago and lasted for about 20 million years” (Katemopoulos, 2017).
 Palm trees first came to Los Angeles by Spanish missionaries in the 18th
century who planted them for religious and practical purposes (Mueller,
2016).

8. PINE TREE
 “Pines are thought to have evolved around 153 million years ago,
although estimates do vary quite widely. The genus Pinus which includes
some important timber species is thought to have diverged from other pines
approximately 95 million years ago” (“Pine Trees,” n.d.).
 The oldest known pine fossil is a cone from the Lower Cretaceous period
from about 130 million years ago and is structurally similar to pine cones
today (Pines - Evolution And Classification, n.d.).
 Evolution of the pine can be separated into three stages, “Mesozoic origin
and diversification, the early Cenozoic fragmentation due to angiosperm
dominance under the equable climates of the Eocene, and Oligocene and
Miocene diversification due to expansion of fire-prone and abiotically
stressful habitats” (Keeley, 2012).

9. ROCKS

10. QUARTZITE
 Characteristics
 Quartzite is a metamorphic rock that is created when quartz-rich
sandstone or chert is exposed to high temperature and pressure
(Geology - Rocks and Minerals, n.d.).
 Quartzite can come in many different colors due to impurities, but
pure quartzite is white.
 My thoughts
 This might be quartzite due to its grainy feel and glassy look. It also
seems to have visible quartz crystals imbedded which is a main trait
of quartzite.

11. CONGLOMERATE
 Characteristics
 Conglomerate is a sedimentary rock that is made up of rounded
clasts that are greater than two millimeters in diameter
(Conglomerate: Sedimentary Rock - Pictures, Definition & More, n.d.).
 Conglomerate is bound together by a cement that is usually made up
of calcite or quartz.
 Conglomerate clasts are usually made up of rocks that have been
washed downstream or down current. Conglomerate is usually found
near streams, lakes, and oceans since that is usually where those
conditions are met.

12. CONGLOMERATE CONT.
 My thoughts
 I initially thought that this rock that I found was conglomerate because it looked like a rock that had many clasts in it.
 Upon closer inspection, this might just be a piece of concrete that broke and found its way along the trail.
 Other reasons why this can’t be a conglomerate is because there is no source of running water near me that can form a proper
conglomerate and that the clasts aren’t well rounded at all.

13. GRANITE
 Characteristics
 Granite is an igneous rock that is lightly colored and has grains that
are big enough to be seen without aid (Granite: Igneous Rock -
Pictures, Definition & More, n.d.).
 Granite is made of quartz and feldspar which gives it a red, pink, gray,
or white color and has dark mineral grains across the rock.
 My thoughts
 Based on this description and my image, I have reason to believe
that this rock is granite since it is a lightly colored rock with black
grains, and it is one of the most common rocks to find. I am not
sure what rock this is specifically.

14. LIMITATIONS
 There weren’t any rock formations near me that show any geological laws and principles as well as
unconformities.
 There is the Eagle Rock Canyon Trail, but it is a short one-mile trail that is lackluster and not very canyon-like
so there was nothing of note there.
 A better site for rock formations would have been Bronson Canyon in Griffith Park which has a much better
hiking trail or somewhere less urbanized such as Vasquez Rocks near Santa Clarita.

15. Photo of Vasquez Rocks (Olsen, n.d.) Photo of Bronson Canyon (Clark, n.d.)

16. REFERENCES
 Conglomerate: Sedimentary Rock—Pictures, Definition & More. (n.d.). Retrieved August 11, 2021, from
https://geology.com/rocks/conglomerate.shtml
 Clark, J. (n.d.). Photo of Bronson Canyon . BusinessYab.
https://cdn.businessyab.com/assets/uploads/aed119c5703d731fa2116d8536162f7b__united_states_california_los_angeles_county_l
os_angeles_central_la_canyon_drive_3200_bronson_canyonhtml.jpg.
 Geology—Rocks and minerals. (n.d.). Retrieved August 11, 2021, from
https://flexiblelearning.auckland.ac.nz/rocks_minerals/rocks/quartzite.html
 Granite: Igneous Rock—Pictures, Definition & More. (n.d.). Retrieved August 11, 2021, from https://geology.com/rocks/granite.shtml
 Horspool, S. (2021, March 22). How Feral Peacocks Stay Alive in Urban Neighborhoods. PetHelpful. https://pethelpful.com/birds/Wild-
versus-Feral-Peacocks-in-Southern-California
 Katemopoulos, M. (2017, September 21). The History of Palm Trees. Garden Guides. https://www.gardenguides.com/79522-history-
palm- trees.html

17. REFERENCES
 Keeley, J. E. (2012). Ecology and evolution of pine life histories. Annals of Forest Science, 69(4), 445–453. https://doi.org/10.1007/s13595-012-
0201-8
 Mueller, N. (2016, January 21). How The Palm Tree Came To Southern California. Garden Collage Magazine.
https://gardencollage.com/wander/gardens-parks/palm-trees/
 Naish, D. (2013, January 17). The other peacock. Scientific American Blog Network. https://blogs.scientificamerican.com/tetrapod-zoology/the-
other-peacock/
 Olsen, E. (n.d.). [Photo of Vasquez Rocks]. https://i1.wp.com/californiascienceweekly.com/wp-content/uploads/2020/01/vasquez-rocks-
drone1.jpg?w=1200&ssl=1
 Palm—New World Encyclopedia. (n.d.). Retrieved August 9, 2021, from https://www.newworldencyclopedia.org/entry/palm
 Pine Trees. (n.d.). Basic Biology. Retrieved August 10, 2021, from https://basicbiology.net/plants/gymnosperms/pine-trees
 Pines—Evolution And Classification. (n.d.). Retrieved August 10, 2021, from https://science.jrank.org/pages/5234/Pines-Evolution-
classification.html
 The Los Angeles Basin—A Huge Bowl of Sand. (n.d.). Retrieved August 10, 2021, from http://www.laalmanac.com/geography/ge08e.php